Ice sheets melt in a complex process that has an impact on climate and oceanography.

Illustration by National Geographic Art
  • On September 14, 2007, Arctic sea ice shrunk to the smallest area in recorded history. The European Space Agency (ESA) identified the loss of ice using satellite readings. The ESA reported that ice coverage had declined more than 1 million square kilometers (386,102 square miles) since 2006. This one-year loss of ice far exceeds the annual average decline of 100,000 square kilometers (38,610 square miles) per year.

    Shrinking sea ice provides evidence that the Arctic is warming. In fact, the Arctic is warming much faster than lower latitudes. The loss of ice will have many effects around the world, including sea level rise, changing precipitation patterns, altered wildlife migration routes, and increased opportunities in Arctic shipping lanes. Policymakers will need to address these issues to better prepare for the environmental, economic, and social consequences of vanishing sea ice.

  • Term Part of Speech Definition Encyclopedic Entry
    alter Verb

    to change.

    annual Adjective


    Arctic Noun

    region at Earth's extreme north, encompassed by the Arctic Circle.

    Encyclopedic Entry: Arctic
    consequence Noun

    result or outcome of an action or situation.

    economic Adjective

    having to do with money.

    evidence Noun

    data that can be measured, observed, examined, and analyzed to support a conclusion.

    latitude Noun

    distance north or south of the Equator, measured in degrees.

    Encyclopedic Entry: latitude
    migration route Noun

    path followed by immigrants to a new region.

    policymaker Noun

    person or organization responsible for creating government or organizational rules and behavior.

    precipitation Noun

    all forms in which water falls to Earth from the atmosphere.

    Encyclopedic Entry: precipitation
    satellite Noun

    object that orbits around something else. Satellites can be natural, like moons, or made by people.

    sea level rise Noun

    increase in the average reach of the ocean. The current sea level rise is 1.8 millimeters (.07 inch) per year.

    Encyclopedic Entry: Sea Level Rise
    shipping Noun

    transportation of goods, usually by large boat.

    vanish Verb

    to disappear.

    wildlife Noun

    organisms living in a natural environment.